The first thing I remember is Zork. The year I was born, four guys who had invented a programming language at MIT released an interactive text "computer game" that went by the futuristic, silly but imposing name, Zork. It's difficult to remember computers as they were then without our current sense of technological sophistication (or should that be naivety?). My father worked in IT, so there were computers in my house from an early age. I remember vividly my older siblings being taught to "code"; to enter strings of commands to form a short "program" that meant the computer did something like change its screen colour or show a moving triangle.

Most of us remember the blackness of DOS, its blinking, patient but demanding cursor. This was a time when it felt that the depths of your machine were on show. You turned it on and there were its black innards, waiting to be ploughed through, vulnerable, demanding, endless. There was none of the pretty, cheery Apple design or the blue chiming order of Windows. We were yet to build a cosy home from these raw materials. No, DOS was as open and black as the American plains at night and as scary. But there were prizes to be won for those brave enough to tame the frontier.

And what those of us who remember DOS realise now is that we are protected from how a computer actually works: how to code, design or run a program. We have tamed the frontier and so lost those basic skills. Few of us would give up our sleek, compliant virtual homes to be out in the cold night again, but there was an excitement to that blackness. Out of that blackness sprang one of the first stories I remember being told.

Zork was a text-based computer game, which just meant that from a black screen, sparse white text appeared, telling you where you were, what was happening and then awaiting instruction. "You are standing in an open field," it began, "west of a white house, with a boarded front door. There is a small mailbox here."

Then you would type in what you wanted to do. No multiple choice, no avatar, you would type in… anything. It's difficult to explain the thrill this was to a tiny, book-obsessed child who had recently learned to read; cushion tucked beneath her bottom, eyes reflecting the screen's glow, Ribena poised dangerously by the keyboard. It was asking me what to do next. It was asking me to join the story.

You remember that exciting bit in Big where the newly adult Tom Hanks designs the next major toy: an electronic comic book where the reader can make choices along the way that affect the ending? Well, congratulations, dude, you just invented gaming eight years after reality.

Of course, it was also rubbish, in a way. It recognised only a limited range of words to do with direction or action, and it was easy to get stuck being repeatedly killed by a grue in a cave, but it was genuinely spooky and you had no idea what would happen next. There were clockwork birds and a "sinister lurking presence" and so much darkness that you were narratively, textually, literally pressing through. It was clear that there were authors to this midnight-black adventure. You could tell because when you put in rude words instead of commands (as I defy anybody to resist doing, whether it's Zork or Siri on your new iPhone 4S), the game recognised them and chided you with appropriate twinkle. At that point, a tiny girl in her dad's office and four grown men at MIT bonded. In a totally OK way.

From this point, my journey was Sega-bound. The Gamesmaster, the Mega Drive. There were those who went the Nintendo route with its lighter colours and squat Mario bouncing. I eschewed them. You were Nintendo or you were Sega and ne'er the twain should go round each other's house for tea. I can still hear the voiceover from the Mega Drive's Altered Beast. I can still do an uncanny impression of the sounds Ryu made when he threw a fireball on Street Fighter. So why did I become an avid gamer, while many, in those days at least, did not?

'It’s difficult to explain the thrill Zork was to a tiny, book-obsessed child; it was asking me to join the story.' Photograph: Magali Delporte for the Observer

I think it's linked to writing. Like writing, gaming is essentially private and individual (although it really doesn't have to be). It is creative, in comparison to the passivity of watching a film or reading a book. You are making choices and, often, are even designing the world yourself. And, perhaps most crucially, it is controlling.

The writer has a bizarre and ridiculous response to struggling with their environment. Even the actor, faced with their place in the order of things, has the relatively sane response of becoming adept at changing themselves better to suit the world. The writer, thwarted and disappointed by their existence, storms upstairs, slams the door and seethes: "If that's what the world's like, I'm going to create my own…" What closer analogy is there to the powerless teen who retires into SimCity or Civilization to build and rule over some other, smaller characters for a while?

Nowadays, for example, it is common practice to be able to design, down to the smallest detail, the avatar of the character you are playing. This is a welcome element of choice for those of us sick of playing musclebound white men who say things such as: "Come on! It's killing time", seemingly unaware of any double meaning. So I pathetically try to design the body and face of my player to be exactly like mine. Not better, not the dream virtual version of me, the actual version of me, with bad teeth and love handles. The satisfaction inherent in my self "entering the game" became less pleasing recently as the Fable series or Saints Row 3 realistically age your character as time passes. So loading a game for me involves greeting an accurate representation of my fast-fading looks and then into the horrors to come.

But that does not mean it is simply an expression of megalomania. As with writing, out of the megalomania comes a way actively to fight loneliness. We recognise the power of literature to move us when, as Alan Bennett puts it in The History Boys: "The best moments in reading are those when you find a passage that seems to have been written just for you. And it's as if a hand has come out and taken yours."

Gaming was littered with these for me, as the community felt small and interested in the same things. Monkey Island had a hilarious, self-mocking attitude to its own form that TV wouldn't discover until Chris Morris. The futuristic detective adventure Ripper came with four different endings and a sense of impending and darkening horror that outdid any of the glossy, simplistic 90s serial-killer movies. They spoke to me.

Playing a game is more social than watching a film. Watching a film may as well be done separately as together. There may be an hour or so after the film where you fight over its quality or wearily accept that you all think pretty much the same thing, but you watch it in silence and with no sense of creativity or problem-solving or shared peril. Playing a game with someone is active throughout. "Watch out!"; "Go there!"; "What about jumping over the hole?" are all pretty irritating things to hear, but often helpful and certainly interactive.

And now you can literally play alongside each other as comrades or enemies. Back when a new PC adventure game arrived in my house as a child, we would all take it in turns to play and if there was a particularly difficult bit to get past, you can bet the child or adult who finally got Lara Croft to stop mindlessly jumping against that bit of wall would garner respect. That's a pretty unusual thing to come across as a kid.

So why do computer games now have the poor reputation they do? Well. There are a few answers to that. One is: "They don't, it's a $68bn industry rivalling film and television and it certainly doesn't need your help." Quite. But you know what I mean. Because it's sedentary, I think, is one thing. There's a middle-class terror of bringing up fat children and the idea of raising a chubby automaton who spends all day shooting people in the head while calling for more Doritos is more than Sara and Toby can bear. (Never mind that no one ever lost any weight reading, the holy grail of youthful hobbies, as I can vouch, having been exactly the sort of overweight, bookish ball of rage who hid in a shed writing poetry to avoid sports.)

But even if this were a valid criticism, companies have been falling over themselves to provide physically interactive gaming, beginning with the Wii (a flawed, lazy console, in my opinion, which if you own, you are basically on Nintendo's side and you can't borrow any of my dolls) but including the brilliant Xbox Kinect, which allows you to use the whole body as a controller and is exhausting and exhilarating in equal measure.

But perhaps the real problem is that most of the high-profile games are obsessed with violence and with warfare in particular. When there is a school shooting or any other act of violence from a relatively young person, the shooters the shooters played are always reeled out, just as film, television and music have all been called on before, to display exactly how this erosion of morality began. No mention that everyone else of that generation was playing them too and somehow managed not to become convinced that by walking over food or ammunition they would somehow magically "pick them up". "But don't you know they use Call of Duty to desensitise soldiers before they send them out to Afghanistan?" I hear people say. "How can you possibly support that?" As if the most reprehensible thing about sending a teenager to another country to kill strangers is the manner in which we attempt to prepare them.

Anyone who has ever been unfortunate enough to suffer violence, or to perpetrate it, understands inherently that there is a difference. It is surprising and heartening how few of us in the west have, when we think about it. But the crack of a fist against jaw in real life, or the scream of a man from an alley, or the sight of blood in a woman's hair between blows – these are moments that, when actually experienced, fade the fake destruction of worlds on a screen into mute monochrome. Real violence is never forgotten. And it belittles it and patronises people to imagine that we cannot tell the difference.

What I think has changed is the prevalence of the antihero as protagonist, not just in gaming, but in entertainment in general. The 70s gave us a golden age of cinema and one in which for the first time real moral complexity was awarded to life's outsiders in central parts. In the very early adventure games for PC, Sierra produced a series with names such as Police Quest, Space Quest and King's Quest in which you explored a world and solved problems in the guise of a policeman, space explorer or (get this) member of a royal family.

It's difficult to imagine that now. Since then, there has been a generational tendency to move the traditional villain towards the centre of the action. You see this in great art (The Sopranos) as well as more schlocky fare. There are many cultural arguments as to why this may be, including the maturing and souring of America as a global superpower and cultural hegemon and so in its self-representation, or the general, gradual decline in idealism that accompanied the end of the cold war. Whatever the reason, you're more likely now to be playing the criminal than the law enforcer in games.

I hadn't really even noticed this until recently playing LA Noire, in which your character is an uncorrupt policeman in the 1940s and this came as such a shock to me that I kept trying to make decisions within the game that would get me into trouble, convinced that that must be the narrative's way forward. In fact, the only area where violence is both plentifully available within the narrative and yet legally and culturally acceptable is, you guessed it, warfare, so no wonder they keep churning those games out. Perhaps it reveals more about us as a society than the morals of "gamers".

But there should be more games that aren't focused on violence. In an attempt to free us from this moral quagmire, more and more are letting you choose the morality of your protagonist. The charming Fable series and fantastic Infamous games allow you different gameplay and powers, depending on your behaviour within the game and whether you wish to be the hero or the villain of the piece. Yet most serious gamers agree that by far the best new game of the past few years is Portal 2, entirely unviolent and essentially a puzzle game, that forces such lateral thought and creativity in the player that it's more akin to architecture than to war or sport.

Of course there are dreadful games. There are games in which the script seems written by stoned teenagers and games where you feel you have wasted your life repeatedly throwing a grenade at a fat man who keeps killing you. But when you play a good game, when you play a great game, you enter a different world, a world that has been meticulously and beautifully planned for you by designers who care and an author who leads you through a story as well as any author ever has and one that welcomes you back time and time again with new twists and turns each time. The atmosphere is totally encompassing, often unlike anything you've come across before: the chilly Germanic lycanthropy of an old Gabriel Knight game, the unnerving mixture of zombie Stepford wives in an underwater world in BioShock or the brightly coloured, gorgeous Spielberg-esque adventure of Uncharted. You meet characters who stay with you for ever and you make decisions that shape the tale. You try and think and fail again and think and come back later and try and try until you find the key. And if you're lucky, really lucky, a hand reaches out and takes yours.

I may seem laughably sentimental about what's essentially pixels jiggering about. But somewhere deep inside when I was little I wanted to be an artist. And a whole art form has developed in my lifetime. I remember for the first time reading: "Happy families are all alike; every unhappy family is unhappy in its own way." I remember the first time I heard: "I believe in America. America has made my fortune." And I remember standing in an open field, west of a white house, with a boarded front door. There is a small mailbox here.